Scan depth

The depth parameter controls how much metadata is extracted from files, folders, datasets, and databases. Set it once as a global default, or override it for any add entry.

depth: variable                   # global default

add:
  - folder: ./data                # inherits "variable"

  - folder: ./big
    depth: stat                   # override for this entry

  - database: sqlite:///db.sqlite
    depth: dataset

Feature	dataset	variable	stat	value (default)
Folders	✓	✓	✓	✓
Datasets (format, path, mtime)	✓	✓	✓	✓
Variables (names, types)		✓	✓	✓
DB introspection (PK, FK, comments)		✓	✓	✓
Row count, statistics			✓	✓
Enumerations, frequencies, patterns				✓
Auto-tagging (format, security, text)				✓

Note: At depth="variable", CSV and Excel files only extract column names (types require reading data, available from depth="stat"). All other formats provide types at this level.

Typical use cases:

• dataset — quick inventory of available files/tables without reading data
• variable — lightweight schema discovery (column names and types)
• stat — data profiling without enumeration detection (faster than value)
• value — full catalog with frequency tables and enumeration assignment (default)

If you need value frequencies but manage enumerations manually through metadata_path, use auto_enumerations: false with depth: value. Frequencies remain available, but automatic enumeration entities and generated variable links are skipped.

Auto-tagging

At depth="value" (default), string columns are automatically tagged by content type. Tags use a two-level hierarchy under the auto parent:

Category	Tags
Format	auto---email, auto---phone, auto---uuid, auto---iban
Security	auto---bcrypt, auto---argon2, auto---jwt, auto---secret
Text	auto---structured, auto---semi-structured, auto---free-text → auto---natural-text

Each variable receives at most one leaf tag. The frontend can use parent_id to filter by category (e.g. selecting auto---security shows all bcrypt/argon2/jwt/secret variables).

Security-tagged columns (bcrypt, argon2, jwt, secret) have their raw frequency values suppressed — only pattern frequencies are emitted, so no actual secrets appear in the exported catalog.

Policy tags

Policy tags let you manually control scan behavior for specific variables. Like auto-tags, they live under the scan hierarchy and are auto-created — no tag.csv entry needed.

Tag	Effect
policy---frequency-hidden	Suppress all frequency and enumeration data (stats remain visible)

Assign the tag in your variable.csv metadata:

id,tag_ids
source---employees_csv---first_name,"policy---frequency-hidden"

This is useful for sensitive columns that auto-tagging does not flag (e.g. first names, internal IDs, business codes).